So how did Santiago's death save lives?
"Santaigo's death while tragic probably saved lives"
Really? How so?
Yeah i don't think it did. I can't think of any way.
shareCol. Jessup likely believes that a sub-par marine is incapable of serving in a unit and defending his comrades-in-arms. If Santiago was out on a mission with other marines and needed to defend them or carry wounded, or if he was on patrol and had to be vigilant at all times, and he was not capable of any of those tasks, lives could or would be lost.
I do not personally think that there was anything right in the actions taken by the rest of the corps depicted in this film, but that's the point Jessup was making. The correct action would be to drum him out and/or send him back to training until he could hack the job.